凯氏定氮仪蒸馏后滴定法测定防水涂料乳液中氨含量

Kjeldahl Analysis Method for Determination of Ammonia in Latex for Water-Resistant Coatings

建立了测定防水涂料乳液中氨含量的凯氏定氮仪蒸馏滴定法。称取2 g样品,经凯氏定氮仪碱化蒸馏,以硼酸为接收液,用0.01 mol/L的盐酸标准溶液进行滴定。该方法加标回收率为91.3%~96.6%,测定结果的相对标准偏差小于3.0%。与JC 1066—2008附录C中方法测定结果无显著性差异,凯氏定氮仪蒸馏滴定法的准确度、精密度均优于标准方法 JC 1066—2008附录C,而且耗时短,方法可靠,满足涂料及涂料乳液厂商实施原材料及产品监控需要。

The Kjeldahl analysis method fl^r determination of ammonia in the latex for water-resistant coatings has been established. 2 g sample was alkali-distilled via the Kieldahl Azotometer. Boric acid was used as receiving solution, and 0. 01 mol/L hydrochloric acid was used as the standard solution for automatic titration. The recovery of the method was in the range of 91.3%-96. 6%, the relative standard deviation was less than 3.0%. Compared with the appendix C of JC 1066--2008 method, the results detected by this method had no signifi- cant difference. The Kieldahl Azotometer method showed better accuracy and precision than the appendix C of JC 106612008 method, moreover, it was a reliable method which consumed less time, and met the demand on monitoring of raw materials and products.